code: def test_concatenate_self(util):
      clip = BitmapClip([["AAA", "BBB"], ["CCC", "DDD"]], fps=1)
      target = BitmapClip([["AAA", "BBB"], ["CCC", "DDD"]], fps=1)
  
      concatenated = concatenate_videoclips([clip])
  
      concatenated.write_videofile(
          os.path.join(util.TMP_DIR, "test_concatenate_self.mp4")
      )
      assert concatenated == target
  
file_path: moviepy/tests/test_compositing.py
imports: import os
  import numpy
  import pytest
  from moviepy.video.compositing.CompositeVideoClip import CompositeVideoClip, clips_array
  from moviepy.video.compositing.concatenate import concatenate_videoclips
  from moviepy.video.compositing.transitions import slide_in, slide_out
  from moviepy.video.fx.resize import resize
  from moviepy.video.VideoClip import BitmapClip, ColorClip
label_desc: Use image node_id 3 for calling a global function with example usage: test_concatenate_self(util) without return types